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2 years ago

Neha swims in a 90 m long pool. She covers 180 m in

Physics

1 answer:

mario62 [17]2 years ago

3 0

Answer:

speed in m/s is 3m/s

Explanation:

as she swims 90m in 30 seconds

dividing 90 by 30 will give 3m/s

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A car goes from point A to point B, five miles away and then returns to point A. The car is going 15 mph.

Sergeeva-Olga [200]

the velocity would be 0 mph

The answer is B.

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3 years ago

A square coil (length of side = 24 cm) of wire consisting of two turns is placed in a uniform magnetic field that makes an angle

kupik [55]

Answer:

The magnitude of the emf induced in the coil is 60 mV.

Explanation:

We have,

Side of the square coil, a = 24 cm = 0.24 m

Number of turns in the coil, N = 2

It is placed in a uniform magnetic field that makes an angle of 60 degrees with the plane of the coil. If the magnitude of this field increases by 6.0 mT every 10 ms, we need to find the magnitude of the emf induced in the coil.

We know that the induced emf is given by the rate of change of magnetic flux throughout the coil. So,

$\epsilon=N\dfrac{d\phi}{dt}\\\\\epsilon=N\dfrac{d(BA\cos \theta)}{dt}$

$\theta$ is the angle between magnetic field and the normal to area vector.

But in this case, a uniform magnetic field that makes an angle of 60 degrees with the plane of the coil. So, the angle between magnetic field and the normal to area vector is 90-60=30 degrees.

Now, induced emf becomes :

$\epsilon=N\dfrac{d(BA\cos \theta)}{dt}\\\\\epsilon=NA\dfrac{dB}{dt}\cos \theta\\\\\epsilon=2\times (0.24)^2\times \dfrac{6\times 10^{-3}}{10\times 10^{-3}}\times \cos (30)\\\\\epsilon=0.0598\ V\\\\\epsilon=59.8\ V$

$\epsilon=60\ mV$

So, the magnitude of the emf induced in the coil is 60 mV. Hence, this is the required solution.

5 0

3 years ago

a student moves a box across the floor by exerting 23.3 N of force and doing 47.2 J of work on the box. How far does the student

kozerog [31]

Work = Force x Distance
47.2J = 23.3N x d
d = 47.2/23.3
d = 2.0258 m

hope this helps :P

8 0

3 years ago

A bullet is dropped into a river from a very high bridge. At the same time, another bullet is fired from a gun straight down tow

anastassius [24]

Answer:

Option (c)

Explanation:

Both the bullets have same acceleration because they both falls under the influence of acceleration due to gravity.

The bullet which is fired from the gun has some initial velocity but the bullet which is dropped has zero initial velocity.

the acceleration is acting on both the bullets which is equal to the acceleration due to gravity and they both in motion in the influence of gravity.

8 0

3 years ago

What name is used for a high-power variable resistor?

const2013 [10]

The answer would be C: Rheostat. :)

3 0

3 years ago

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